tbuckley/cabot-search huggingface dataset:
TMIC-36. REPROGRAMMING THE GLIOBLASTOMA IMMUNE MICROENVIRONMENT WITH CONVECTION ENHANCED GENE THERAPY REVEALS INTRATUMOR IL6 DRIVES GLIOBLASTOMA IMMUNOSUPPRESSION AND GROWTH
Authors: Jacob S Young, Nam Woo Cho, Calixto-Hope Lucas, Kyounghee Seo, Raquel Santos, S John Liu, Joanna J Phillips, Tomoko Ozawa, Aparna Bhaduri, Manish Aghi, Mitchel S Berger, David Raleigh
Journal: Neuro-Oncology (2022)

Abstract The glioblastoma microenvironment is an immunosuppressive barrier to therapeutic innovation. We hypothesized intratumor convection enhanced delivery (CED) of gene therapy vectors could reprogram the glioblastoma immune microenvironment and elucidate therapeutic vulnerabilities. To test this, SB28 or GL261 glioblastoma allografts were implanted into immunocompetent mice and treated with CED of attenuated adeno-associated virus 9 vectors (AAV9) encoding experimental cytokines (Il1b, Ccl4, or Apoa1) underlying infiltration or activation of anti-tumor immune cells in other intracranial tumors. Serial intracranial bioluminescence was used to assess glioblastoma growth and animals were monitored for survival. The impact of gene therapy perturbations on the glioblastoma immune microenvironment was assessed using histology, immunohistochemistry, single-cell mass cytometry (CyTOF), and multiplexed cytokine assays. Serial body weight and systemic cytokine measurements showed no evidence of treatment toxicity. AAV9-APOA1 or AAV9-IL1B gene therapy CED treatments attenuated SB28 growth and prolonged survival, decreasing immunosuppressive macrophage infiltration and increasing CD8 T cell and microglia infiltration of the glioblastoma microenvironment compared to control AAV9 vectors. Gene therapy CED treatments did not attenuate GL261 growth or prolong survival, but CyTOF of human glioblastomas (n=6) in comparison to preclinical models revealed untreated GL261 glioblastomas were endogenously enriched in CD8 T cells and other lymphoid lineages compared to untreated SB28 or human glioblastomas. Multiplexed cytokine assays demonstrated suppression of intratumor IL6 is a conserved mechanism of action underlying glioblastoma gene therapy responses. Single-cell RNA sequencing analysis of 32,877 cells from human glioblastomas (n=11) showed IL6 is predominantly produced by radial glial like cancer stem cells or endothelial cells in the tumor microenvironment. In support of these findings, survival from intracranial SB28 glioblastomas was prolonged in Il6 knockout C57BL/6J mice compared to wildtype mice. In summary, we report a novel strategy using gene therapy and CED to reprogram the glioblastoma immune microenvironment, revealing IL6 drives glioblastoma immunosuppression and growth.
INNV-07. TUMOR TREATING FIELDS (TTFIELDS; 200 KHZ) POST-MARKETING SAFETY DATA FROM PATIENTS WITH GLIOBLASTOMA TREATED BETWEEN 2011–2022
Authors: Maciej Mrugala, Wenyin Shi, Fabio Iwamoto, Rimas Lukas, Joshua Palmer, John Suh, Martin Glas
Journal: Neuro-Oncology (2022)

Abstract Tumor Treating Fields therapy (TTFields; 200 kHz) is a noninvasive, locoregional, antimitotic treatment approved for newly diagnosed glioblastoma (ndGBM), recurrent (r) GBM, malignant pleural mesothelioma, and is being investigated in additional solid tumors. Approval in GBM was based on results of the phase 3 EF-11 (TTFields monotherapy; rGBM) and EF-14 (TTFields therapy/maintenance temozolomide; ndGBM), which showed clinical benefit without an increase in adverse events (AEs). Here we review post-marketing surveillance (PMS) data from patients with brain tumors who received TTFields therapy over an 11-year period. Unsolicited PMS data from patients with brain tumors who received TTFields therapy between October 2011 and March 2022, were included. Overall 23,822 patients were included in this analysis. Most patients (72%) were from North America; 24% from Europe, Middle East and Africa, and 4% from Japan. Birth year was available for 23,784 patients; of these, the average age at treatment start was 57 years (range: 3–103). Diagnoses were ndGBM (67%), rGBM (27%), astrocytoma (WHO grade 3; 4%) and other (2%). Overall, 71% of patients reported ≥ 1 AE, with the most common being skin reaction (42%), electric (tingling) sensation (14%), heat (warmth) sensation (12%), and seizure (11%). Furthermore, 56% of patients reported AEs possibly related to TTFields therapy, with the most frequently reported being skin reaction (42%), electric sensation (14%) and heat sensation (12%), occurring underneath the arrays. Numbers and types of AEs were comparable between age and diagnosis groups. PMS data from &amp;gt; 23,000 patients with brain tumors show that TTFields therapy (200 kHz) is well-tolerated, consistent with the known safety profile; no new safety signals were identified. TTFields therapy is not associated with systemic toxicity; most common possibly-related AEs are localized dermatologic events that can be managed with appropriate prophylaxis and treatment strategies.
TMIC-01. STAT3 EXPRESSION IN BRAIN METASTASES FROM BREAST CANCER: CORRELATIONS WITH DIFFERENT MOLECULAR SUBTYPES AND CLINICAL OUTCOME
Authors: Alessia Pellerino, Francesco Bruno, Luca Bertero, Elisa Bellini, Alessandra Beano, Filippo Montemurro, Manuel Valiente, Roberta Rudà, Riccardo Soffietti
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND STAT3 expression in peritumoral reactive astrocytes (RA) of brain metastases (BM) from breast cancer (BC) may favor a pro-metastatic environment. MATERIAL AND METHODS Eighty-five BM specimens from BC were identified from the biobank of Pathology Unit of University of Turin and Spanish national BrM network (RENACER). pSTAT3 expression was scored in RA of peritumoral tissue according to Priego et al. (Nat Med 2018). Clinical, molecular data, and intracranial progression (i-PFS) were retrospectively retrieved. RESULTS Median age was of 54 years (range 30–81). Immunohistochemistry for GFAP and pSTAT3 was feasible in 68/85 (80%). 15/68 patients (21.1%) had BM from luminal BC, 27/68 (39.7%) from HER2-positive BC, and 26/68 (39.2%) from TNBC. 56/68 (82.4%) showed positive staining of pSTAT3, of which 9/68 (13.3%) scored with 3, 26/68 (38.2%) with 2, 21/68 (30.9%%) with 1, and 12/68 (17.6%) with 0 (negative). High pSTAT3 expression (score 2-3) was observed in 17/27 (62.9%) BM from HER2-positive BC and in 15/26 (57.7%) BM from TNBC, while most of BM from luminal BC (12/15 – 80%) had low or absent pSTAT3 (score 0-1) (p=0.021). Overall i-PFS was 16 months (range 7-41): low pSTAT3 BM (score 0-1) had a median i-PFS of 21 months versus 12 months for high pSTAT3 BM (score 2-3). A shorter median i-PFS was observed in high pSTAT3 BM from TNBC (4 months) as compared with low pSTAT3 BM (11 months). Conversely, i-PFS of high pSTAT3 BM (7 months) was similar to low pSTAT3 BM (6 months) in HER2-positive BC. CONCLUSION pSTAT3 expression in RA of peritumoral tissue of BM from TNBC and HER2-positive BC is higher than in BM from luminal BC. Of note, patients with high pSTAT3 BM from TNBC progressed earlier in comparison with those with low pSTAT3, suggesting that pSTAT3 expression has an influence on the outcome.
TMIC-63. SELECTIVE TARGETING OF IMMUNE-SUPPRESSIVE LEUKOCYTES TO REPROGRAM THE GBM IMMUNE LANDSCAPE
Authors: Nourhan Abdelfattah, Jose Maldonado, Jia-Shiun Liu, Nhat Tran, Kyuson Yun
Journal: Neuro-Oncology (2022)

Abstract A significant barrier to immunotherapy efficacy is GBM’s immunosuppressive microenvironment composed of few tumor-infiltrating lymphocytes (TILs; &amp;lt; 5%) but abundant myeloid cells, making it an “immune cold” tumor. To enhance immunotherapy efficacy, a better molecular and functional understanding of the heterogeneous cell types in the GBM microenvironment and their function is urgently needed. Single cell RNA-sequencing offers high-resolution cellular and molecular data to elucidate cancer and stromal cell phenotypes at the single cell level to identify the most relevant cell types to target to enhance immune activation. We recently reported an integrated, multi-regional and -dimensional single-cell transcriptomic analysis of 201,986 human glioma and immune cells derived from 44 tissue fragments from 18 human glioma patients. In doing so, we mapped GBM cellular heterotypia and spatial, molecular, and functional heterogeneity of glioma associated immune cells. We observed an extensive spatial and molecular heterogeneity of glioma cells, microglia, macrophages, and T cells within the same tumor samples in low-grade gliomas (LGGs), primary GBMs, and recurrent GBMs. Importantly, our analysis of 83,479 glioma infiltrating myeloid cells identifies 9 molecularly distinct myeloid subtypes: 4 microglia, 4 bone marrow-derived macrophage (BMDM), and dendritic cell subtypes. Importantly, five of these myeloid cell subtype gene signatures were independent predictors of patient survival in multiple datasets, demonstrating the importance of immune cells in disease progression and aggressiveness. Here, we report evidence for heterogeneous cell:cell communication between glioma and immune cells in different regions within a patient, using CellChat, Cellphone DB, and NicheNet tools. We also nominate immune modulators other than PD1/PDL1 and CTLA3 as more promising targets in GBM. Finally, we provide evidence that S100A4 is a promising novel immunotherapy target since its high-level expression is required for immune-suppressive macrophages and Tregs to block T cell infiltration and DC maturation.
EPID-10. SEIZURE CONTROL BY BEVACIZUMAB IN GLIOBLASTOMA PATIENTS
Authors: Caroline Hertler, Katharina Seystahl, Emilie Le Rhun, Georg Wirsching, Patrick Roth, Michael Weller, Dorothee Gramatzki
Journal: Neuro-Oncology (2022)

Abstract Seizures are a frequent symptom in patients with glioblastoma and bear a relevant impact on quality of life. Likewise, anti-epileptic treatment may affect patients’ well-being due to side effects. Here, we assessed whether owing to relieve from edema and intracranial pressure, treatment with bevacizumab for recurrent glioblastoma might contribute to seizure control.We retrospectively analyzed clinical data of adult patients with glioblastoma who were treated with bevacizumab versus a non-bevacizumab-containing regimen for first recurrence of glioblastoma in the Canton of Zurich between 2010 and 2014 and assessed occurrence and dynamics of seizures before and after first recurrence. Categorical and continuous variables were compared by the Chi-square and the Mann-Whitney U test, respectively. Associations of clinical parameters and seizures were analyzed by binary logistic regression.We identified 55 patients with glioblastoma who had received bevacizumab and 61 patients that received a non-bevacizumab-containing regimen at first recurrence. Seizures were noted in 42 of 111 patients (37.8%) during the 12 weeks preceding tumor recurrence. In the non-bevacizumab group, 23 patients (39.0%) still suffered from seizures 3 months after recurrence whereas only 4 patients (7.7%) in the bevacizumab group experienced seizures (p &amp;lt; 0.001). Multivariable binary logistic regression analyses, including sex, age, performance status, extent of resection, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status and first-line treatment confirmed bevacizumab to be inversely associated with seizures in the 12 weeks after first recurrence (odds ratio (OR) 0.23, 95% confidence interval (CI) 0.06-0.94, p = 0.009).Bevacizumab may contribute to a reduction in seizure frequency in patients with recurrent glioblastoma.
TMIC-56. TUMOR CELL ARCHITECTURAL HETEROGENEITY AND SPATIAL INTERACTIONS WITH THE TUMOR IMMUNE MICROENVIRONMENT IN GBM
Authors: Aryeh Silver, Diana Feier, Guimei Tian, Michael Andrews, Mariana Dajac, Changlin Yang, Tanya Ghosh, Dongtao Fu, Christina Von Roemeling, Maryam Rahman, Matthew Sarkisian, Jianping Huang, Jeffrey Harrison, Duane Mitchell, Loic Deleyrolle
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Glioblastoma (GBM) contains cell populations with distinct metabolic requirements, with fast-cycling cells harnessing aerobic glycolysis, and treatment-resistant slow-cycling cells (SCCs) preferentially engaging lipid metabolism. The interaction between immune and tumor cells, and how their metabolic heterogeneity shapes the immune landscape in GBM has yet to be understood. Objectives: The primary objective of this project is to spatially and molecularly decode the GBM microenvironment heterogeneity with a specific focus on unraveling the metabolic links that underlie the interaction of SCCs with the immune compartment. METHODS Multiple murine glioma cell lines coupled with geospatial profiling were used to establish metabolic heterogeneity and communications, while various genetic and pharmacological approaches were applied to assess the effect of disrupting the metabolic interplay between SCCs and the immune system. RESULTS We determined that SCCs exhibit distinct metabolic dependencies, involving preferential lipid metabolism supported by enhanced fatty acid uptake. We also found that SCCs exhibit specific geospatial distribution and that tumor progression is regulated by their interactions with immune suppressive cells, which in turn work against tumor immune rejection by inhibiting T cell anti-tumor activity. The immune microenvironment shaped by SCCs is marked by specific metabolic features enhancing lipid exchange capacities that are exploited by SCCs to support their survival and functions. Importantly, disrupting lipid metabolic exchange sensitized tumors to chemotherapy. CONCLUSION Our results reveal that metabolic interactions between SCCs and tumor-associated immune suppressive cells within the GBM microenvironment play a critical role in the development of drug and immune resistant tumors. This study delineates these metabolic communications and assesses the potential therapeutic effect of disrupting these interactions to treat GBM. The insights generated from this project uncover fundamental principles of the emerging connections between the tumor microenvironment, cell metabolism, anti-tumor immunity, and associated therapeutic vulnerabilities.
TMIC-85. MICROGLIA REPLACEMENT CHANGES THE TRANSCRIPTIONAL PROFILE OF TUMOR ASSOCIATED MYELOID CELLS IN MURINE MODELS OF BRAIN MALIGNANCIES
Authors: Marius Mader, Adrian Rodrigues, Sophia Chernikova, Zheng Hao Samuel Wong, Yuelong Wang, Claudia Petritsch, Marius Wernig, Melanie Hayden Gephart
Journal: Neuro-Oncology (2022)

Abstract Tumor associated microglia and macrophages (TAMs) represent a main cell type of brain malignancies and demonstrate complex interactions with cancerous cells and the tumor microenvironment. These interactions have important implications for the progression and treatment of malignant central nervous system (CNS) tumors. In a non-oncological context, it has been shown that endogenous microglia can be replaced by peripheral hematopoietic cells by genetic or pharmacological intervention. A highly efficient replacement protocol (Shibuya et al, Sci Transl Med 2022, PMID:35294256) utilizing myeloablative bone marrow transplantation (BMT) followed by microglial depletion via pharmacological inhibition of the Colony-stimulating factor-1 receptor (CSF-1R) leads to almost complete repopulation of the CNS myeloid niche by circulation-derived myeloid cells (CDMCs). We investigated if this approach could be utilized to integrate CDMCs into brain tumors and study associated changes in the TAM signature. Microglia replacement in immune-competent mice was followed by intracranial transplantation of syngeneic cell lines of either high-grade glioma (GL261) or breast cancer metastasis (E0771). Lineage tracing proved high intra- and peri-tumoral chimerism of BMT-graft derived cells among CNS myeloid cells in both models two weeks after tumor cell injection. Tumor associated CDMCs (TA-CDMCs) showed a similarly activated morphology as naïve TAMs. We used single cell RNA sequencing of CD45-positive cells to further profile the transcriptomic identity of glioma TA-CDMCs. Pathway enrichment analysis revealed an upregulation of immune response pathways in TA-CDMCs compared to regular TAMs, including the overexpression of genes relevant for the regulation of T cell activation, suggesting possible modification of the glioma immune-environment. Strategies to manipulate the myeloid niche have the potential to provide further understanding of the pathobiology of TAMs and to build the basis for novel cell therapeutic approaches in the neuro-oncological domain.
TMIC-44. TARGETING BRACHYURY REPROGRAMS ENDOTHELIAL TRANSDIFFERENTIATION OF GLIOBLASTOMA
Authors: Wesley Hsu, Aqib Zehri, Yunping Hu
Journal: Neuro-Oncology (2022)

Abstract Glioblastoma (GBM) is the most common and aggressive primary brain tumor with a median survival of only 15 months and a 5-year survival of less than 5% despite the best available treatments. Tumor recurrence/progression and therapy resistance are major obstacles for GBM treatment. GBM is characterized by intensive vascular proliferation that is associated with tumor cell growth, invasion, resistance to chemo/radiotherapy, and decreased disease-free survival. Increasing data have shown the existence of cells with endothelial characteristics called tumor derived endothelial cells, which come from the transdifferentiation of GBM cells and, more specifically, from GBM stem cells (GSCs). However, the molecular mechanisms underlying this process remain largely unknown. GSCs are tightly regulated by distinct transcriptional programs that are driven by nuclear transcription factors. Brachyury is a transcription factor expressed in normal, undifferentiated embryonic notochord in the axial skeleton and plays an important role in stem cell development and differentiation during normal embryonic development. Here, we show that brachyury is highly expressed in patient-derived GBM cells. Functional studies demonstrate that brachyury is regulated by fibroblast growth factor receptor 1 (FGFR1)/mitogen-activated protein kinase (MAPK). Our studies further disclose that FGFR1/MAPK-directed brachyury activation promotes GSC survival and endothelial formation via vascular endothelial growth factor receptor 2 (VEGFR2), whereas pharmacological inhibition of FGFR1 and MAPK or shRNA-mediated downregulation of brachyury decreases GSC transdifferentiation into endothelial cells and suppresses GBM cell growth and stemness via VEGFR2. Our findings highlight the importance of FGFR1/MAPK-regulated brachyury activation in GSC transdifferentiation into endothelial cells via VEGFR2, and targeting the FGFR1-MAPK-brachyury-VEGFR2 signal pathway may represent a novel therapeutic strategy by reprogramming GSCs driving vascular transdifferentiation and tumor progression.
TMIC-59. GLIOBLASTOMA INDUCES THE DIFFERENTIATION AND RECRUITMENT OF NON-CANONICAL ANTI-TUMORAL NEUTROPHILS FROM SKULL BONE MARROW
Authors: Meeki Lad, Angad Beniwal, Saket Jain, Sabraj Gill, Manish Aghi
Journal: Neuro-Oncology (2022)

Abstract The effects of tumor-associated neutrophils (TANs) on glioblastoma biology remain poorly understood. Flow cytometric analysis of 5 newly diagnosed glioblastoma fresh tissue specimens surprisingly revealed a high fraction (21.0-34.1%) of TANs expressed MHCII, a marker of antigen-presenting cells not classically associated with neutrophils and not expressed in matched peripheral blood (PBNs). Transcriptomic profiling confirmed that patient TANs upregulated expression of MHCII subunits (HLA-DR), chaperones (HLA-DM), and costimulatory ligands (CD86/83). Ex vivo cocultures further demonstrated that TANs activated patient-matched naïve T cells in an MHCII-dependent manner, while PBNs did not (CD25 MFI fold-change: 1.1 vs 3.2, p&amp;lt; 0.001). The antitumoral relevance of this property was confirmed in a syngeneic mouse glioma model, wherein αLy6G-mediated neutrophil depletion in T-cell-competent mice (Balb/c, n= 13) yielded endpoint tumors that had reduced CD8+ T cell infiltration (p= 0.0024) and were 2.4-fold larger by BLI (p= 0.0383) than controls, but had no bearing on tumor burden in T-cell-deficient (athymic) mice. Given the absence of MHCII+ neutrophils in circulation, we interrogated the inducibility of this phenotype by tumor-conditioned media in murine marrow/blood, finding that only immature Ly6Glow bone marrow neutrophils had sufficient plasticity to express MHCII and process foreign antigen as measured by DQ-ovalbumin uptake/proteolysis. Because of the non-inducibility of PBNs, we investigated the hypothesis that MHCII+ TANs were recruited to the glioblastoma microenvironment from adjacent skull bone marrow by labeling this space with CFMDA in tumor-implanted mice; at 72h, skull marrow-derived neutrophils contributed disproportionately to MHCII+ TANs compared to all TANs (41.7% vs 9.3%). As confirmation, in the first-ever scRNA-seq of human TANs, we demonstrated via pseudotime analysis that MHCII+ neutrophils represent a developmental lineage seen in TANs but not matched PBNs. Given the immunostimulatory effects of this population, mechanisms to promote neutrophil egress and tumor infiltration from the skull marrow may have therapeutic value.
TMIC-14. DIFFUSE P16INK4A EXPRESSION IS ASSOCIATED WITH TUMOR CELL SENESCENCE AND SENESCENCE-ASSOCIATED SECRETARY PHENOTYPE RELATED TO IMMUNE MICROENVIRONMENT IN GLIOBLASTOMAS
Authors: Tae Hoon Roh, Young Hwa Kim, So Hyun Park, Soyeong Eom, Tae Jun Park, Jang-Hee Kim, Se-Hyuk Kim
Journal: Neuro-Oncology (2022)

Abstract Cellular senescence (CS) is a state of irreversible cell cycle arrest, and the expression of p16INK4a in cells is one of the reliable markers for CS. However, senescent cells are metabolically active with the senescence-associated secretory phenotype (SASP), which can influence the tissue microenvironment by paracrine signaling to the adjacent tumor, non-tumor, and immune cells. In the present study, we evaluated p16INK4a expression in glioblastoma and investigated its association with CS and SASPs. We analyzed the expression of p16INK4a in 73 glioblastomas by immunostaining. To examine the association of p16INK4a expression and CS, we performed senescence-associated β-galactosidase (SA-β-Gal) staining, a standard marker of CS, using glioblastoma cell lines and fresh frozen tumor tissues. For SASPs analysis, RNA sequencing with Gene Set Enrichment Analysis (GSEA) was performed. Among 73 glioblastomas, twenty-eight cases (38.4%) revealed diffuse strong p16INK4a expression in tumor cells. The glioblastoma with diffuse p16INK4a expression (GMDP) patients were younger (52.4 vs. 59.2 years) and showed prolonged overall survival (median: 25.5 vs. 12.3 months) compared to those harboring negative expression. In vitro analysis, p16INK4a over-expressed glioblastoma cell line showed increased expression of SA-β-Gal which indicates CS. In addition, fresh frozen tissues from GMDP also revealed SA-β-Gal positivity. RNA sequencing analysis revealed that splicing or protein biosynthetic genes were enriched in GMDP, and GSEA showed significant enrichment of SASP genes (false discovery rate &amp;lt; 0.05), especially chemokines associated with monocytes and macrophages. Our data suggest that increased expression of p16INK4a in glioblastoma is associated with tumor cell senescence, and SASPs from senescent tumor cells could be one of the crucial modulators in the tumor immune microenvironment.